Our research efforts are directed toward defining the composition and function of regulatory and contractile proteins that maintain neuronal activity specifically as it relates to the uptake, storage and release of neurotransmitters by synaptosomal nerve endings. Regulatory and contractile brain proteins are structurally assembled into specific filaments and lattices and among these, a new protein named "clathrin," has been characterized as a mechanochemical protein involved in the formation of lattices around vesicles. Such vesicles are involved in the retrieval of putative neurotransmitter substances externalized by the synaptosome and the recycling of vesicular membrane materials. Our immediate goals are to study a) the proteins that regulate the assembly of filaments of actin and other related filamentous structures; b) the binding of those proteins to subcellular organelles (vesicles, membranes); and c), their precise distribution within the synaptosomes. We shall carry out these studies using established biochemical and biophysical methods in addition to immunological techniques which have been standardized in our labratories with antibodies purified by affinity chromatography and conjugated with ferritin, peroxidase or fluorescein as markers. We intend to define the precise involvement of regulatory and contractile mechanisms that produce neuro-active compounds to be incorporated into specific structures such as vesicles and their release at particular sites in the nerve endings. We shall attempt to determine if the junctions of nerve endings contain, among their components, structural proteins involved in contractile events. A strong candidate is alpha-actinin, which has been isolated from brain symaptosomes and characterized in our laboratories. We are attempting to determine if this component is a transmembrane protein connected to carbohydrate moieties included between membranes of synaptic junctions in brain.